Jaguar XK-SS Road Test

How vivid was the performance of the racer--for-the-road Jaguar XK-SS? The XK-SS seldom found its way into professional road-test hands, but Road & Track clocked one at 5.2 seconds 0-60 and through the standing quarter-mile in 14.1 at a little over 100 mph.

That was despite considerable wheelspin due to the lack of a limited-slip differential, but another example tested by The Autocar pretty well confirmed those numbers.

Jaguar XK-SS restored vintage racer
©2007 Jaguar Cars and Wieck Media Services, Inc.
The Jaguar XK-SS used the full racing
powertrain of the customer
D-Type.

The traditional 3.54:1 rear-end gearing of other Jaguar street cars was rather short for the XK-SS, so top speed was limited by the 5,800-rpm redline to 144 mph. In all, stupendous performance for the day -- for just about any day, in fact. But enjoying it took some commitment.

As the cockpit was basically identical to the D-Type's, accommodation was none too generous. The passenger side was especially cramped in foot room. In America, that passenger sat watching the oncoming traffic, because no XK-SS was built as a "left-hooker." The passenger also had to put up with heat beating through the aluminum cockpit side from the left-mounted exhaust system.

The driver had more fun, though it was fun of a demanding sort. While the engine retained much of the tractability for which the XK powerplant was long renowned, it did have racing cams, so its power was concentrated in the upper third of the rev band.

Also, because the D-Type engine had no specific flywheel, it responded vividly to the throttle. Both characteristics made smooth engagement of the abrupt multi-plate racing clutch all the harder.

There were other functional quirks that rendered the XK-SS a questionable proposition as a true dual-purpose vehicle. Some drivers familiar with the D-Type felt that the SS chassis flexed a little by comparison, because it didn't have the cockpit center brace.

Then there was that bulky exhaust system, which apparently was pretty noisy and probably not hard to scrape on a curb. Prolonged urban slogging risked running the battery down, because the generator (no alternators yet) was set up to need more than 2,000 engine rpm to charge.

When the time came to top up the huge rubber-bag gas tank, the same 44-gallon (U.S.) item that filled the shapely tail of the D-Type, it had better not be raining, because the top had to be dismantled to get at the racing-type fuel port.

On the good side, ride quality was described as surprisingly comfortable. The windshield seemed to work well, though it was something less than graceful to look at. And though the steering suffered some of the kickback over bumps characteristic to rack-and-pinion mechanisms, it was quite quick at 2.3 turns lock-to-lock on a 32-foot turning circle, yet pleasingly light.

There was a noticeable tendency to under steer that had been deliberately built into the D-Type for stability at LeMans, and which proved to work well on the highway. Yet whenever a corner seemed too tight, there was plenty of poke to get the tail out. The all-wheel disc brakes, of course, were fabulous.

Sixteen cars were built up from scratch -- more accurately, from incomplete D-Type chassis. Two more finished D-Types were converted to XK-SS specification, one apparently the very car that had finished second at LeMans 1954 and was later tested for Autosport by John Bolster. (On the other hand, several owners of cars originally built as XK-SSs subsequently converted them to D-Type spec.)

Then, overnight, production ended. Was such a super-sports concept too virile to be as popular as one might have expected? Perhaps, but we will never really know. On the night of February 12, 1957, only three weeks after the XK-SS had been formally introduced, the part of the Browns Lane factory where it was built caught fire. Several incomplete chassis and many parts were destroyed; more crippling, so were most of the jigs and tooling.

Thanks to enormous effort and dedication, production of normal cars was going again within days, but it just wasn't worth restarting the XK-SS line. So in a flash, Jaguar was out of the super-sports business, though perhaps that wasn't entirely bad. But there was a lot of obvious good in the basic idea of a sports car built on D-Type lines, and it was worth pursuing.

For more on Jaguar and other great cars, see:

  • Jaguar Cars: Check out more information on the great sporting cars.
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  • New Jaguars: Reviews, ratings, prices, and specifications on the current Jaguar lineup from the auto editors of Consumer Guide.
  • Used Jaguars: Reviews, recalls, trouble spots, and more on pre-owned Jaguars starting with the 1990 model year. From the auto editors of Consumer Guide.